1. Field of the Invention
This invention is directed generally to apparatus and methods for filtration of a cooking substance in a cooking systems, such as a deep fat fryer, and more specifically to a central filtration system and method.
2. Description of Related Art
Large capacity pressurized deep fat fryer cookers (referred herein as deep fat fryers, cooking devices, cookers, and the like) have been devised for cooking products in a heated and or pressurized environment. Typically such devices comprise a cooking vessel, which may be filled with a type of cooking substance (e.g., oil or shortening) and heating devices surrounding or immersed in the vessel for heating the cooking oil. Products to be cooked are placed in the vessel, either directly or possibly contained in a wire basket, and are cooked for a desired length of time.
While such cooking devices described above provide for a relatively effective cooking environment, a problem exists with these devices. Specifically, the cooking substance used in these cooking devices looses some of its effectiveness as it becomes contaminated with suspended particles of food, or "cracklings." This can result in, inter alia, decreased heat capacity for the cooking substance, incomplete cooking, unappealing appearance of the cooked food, and an unappealing taste.
Generally, "cracklings" are pieces of breading, skin, or other items which have separated from a food item being cooked in the fryer. For example, if fried chicken pieces are being cooked within the vessel, some of the breading applied before cooking the chicken may break away from the chicken and drift to the lower zones of the vessel. In the lower portions of the cooking vessel, the cracklings are less likely to cause degradation of the cooking substance in contact with the food products. Because moisture may be found within the cracklings, such moisture may cause the cooking substance to boil over if the cracklings become mixed with the hot oil in the upper zones of the vessel. Further, if the temperature in the bottom of the cooking vessel is too high, the cracklings may burn, causing oxidation of the cooking substance. Such oxidation reduces the useful life of the cooking substance.
Filtration of the cooking substance is a large task. Some fryers include an internal cooking substance filtration system to remove cracklings and other undesirable solids from the cooking substance. The cooking substance from the fryer is drained into a filtration system, where the cracklings are filtered and the cooking substance is cleaned. However, fryers having internal filtration systems tend to be expensive, and the filtration systems often require a significant amount of maintenance.